SPARKC-686 Port to Scala 2.13

Major changes:
* Migrate from scala.collection.JavaConversions to
  scala.jdk.CollectionConverters
* Migrate some uses of Seq to immutable.Seq

Author: Marquis Wong

.github/workflows/main.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        scala:  [2.12.10]
+        scala:  [2.12.11, 2.13.8]
         db-version: [6.8.13, 5.1.24, 3.11.10, 4.0-rc2]
 
     steps:

build.sbt

@@ -4,10 +4,11 @@ import sbt.{Compile, moduleFilter, _}
 import sbtassembly.AssemblyPlugin.autoImport.assembly
 
 lazy val scala212 = "2.12.11"
-lazy val supportedScalaVersions = List(scala212)
+lazy val scala213 = "2.13.8"
+lazy val supportedScalaVersions = List(scala212, scala213)
 
 // factor out common settings
-ThisBuild / scalaVersion := scala212
+ThisBuild / scalaVersion := scala213
 ThisBuild / scalacOptions ++= Seq("-target:jvm-1.8")
 
 // Publishing Info
@@ -70,6 +71,7 @@ val annotationProcessor = Seq(
 def scalacVersionDependantOptions(scalaBinary: String): Seq[String] = scalaBinary match {
   case "2.11" => Seq()
   case "2.12" => Seq("-no-java-comments") //Scala Bug on inner classes, CassandraJavaUtil,
+  case "2.13" => Seq("-no-java-comments") //Scala Bug on inner classes, CassandraJavaUtil,
 }
 
 lazy val root = (project in file("."))

connector/src/it/scala/com/datastax/spark/connector/CassandraJavaUtilSpec.scala

@@ -3,7 +3,7 @@ package com.datastax.spark.connector
 import com.datastax.spark.connector.ccm.CcmBridge
 import com.datastax.spark.connector.cluster.DefaultCluster
 
-import scala.collection.JavaConversions._
+import scala.jdk.CollectionConverters._
 import scala.concurrent.Future
 import org.apache.spark.rdd.RDD
 import com.datastax.spark.connector.cql.CassandraConnector
@@ -117,9 +117,9 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
 
     val rows = results.all()
     assert(rows.size() == 3)
-    assert(rows.exists(row ⇒ row.getString("value") == "one" && row.getInt("key") == 1))
-    assert(rows.exists(row ⇒ row.getString("value") == "two" && row.getInt("key") == 2))
-    assert(rows.exists(row ⇒ row.getString("value") == "three" && row.getInt("key") == 3))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "one" && row.getInt("key") == 1))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "two" && row.getInt("key") == 2))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "three" && row.getInt("key") == 3))
   }
 
 
@@ -140,9 +140,9 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
 
     val rows = results.all()
     assert(rows.size() == 3)
-    assert(rows.exists(row ⇒ row.getString("value") == "one" && row.getInt("key") == 1))
-    assert(rows.exists(row ⇒ row.getString("value") == "two" && row.getInt("key") == 2))
-    assert(rows.exists(row ⇒ row.getString("value") == "three" && row.getInt("key") == 3))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "one" && row.getInt("key") == 1))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "two" && row.getInt("key") == 2))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "three" && row.getInt("key") == 3))
   }
 
   it should "allow to save beans with transient fields to Cassandra" in {
@@ -162,9 +162,9 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
 
     val rows = results.all()
     assert(rows.size() == 3)
-    assert(rows.exists(row ⇒ row.getString("value") == "one" && row.getInt("key") == 1))
-    assert(rows.exists(row ⇒ row.getString("value") == "two" && row.getInt("key") == 2))
-    assert(rows.exists(row ⇒ row.getString("value") == "three" && row.getInt("key") == 3))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "one" && row.getInt("key") == 1))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "two" && row.getInt("key") == 2))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "three" && row.getInt("key") == 3))
   }
 
   it should "allow to save beans with inherited fields to Cassandra" in {
@@ -184,7 +184,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     val rows = results.all()
 
     rows should have size 3
-    rows.map(row => (row.getString("value"), row.getInt("key"), row.getString("sub_class_field"))).toSet shouldBe Set(
+    rows.asScala.map(row => (row.getString("value"), row.getInt("key"), row.getString("sub_class_field"))).toSet shouldBe Set(
       ("one", 1, "a"),
       ("two", 2, "b"),
       ("three", 3, "c")
@@ -210,9 +210,9 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
 
     val rows = results.all()
     assert(rows.size() == 3)
-    assert(rows.exists(row ⇒ row.getString("value") == "one" && row.getInt("key") == 1))
-    assert(rows.exists(row ⇒ row.getString("value") == "two" && row.getInt("key") == 2))
-    assert(rows.exists(row ⇒ row.getString("value") == "three" && row.getInt("key") == 3))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "one" && row.getInt("key") == 1))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "two" && row.getInt("key") == 2))
+    assert(rows.asScala.exists(row ⇒ row.getString("value") == "three" && row.getInt("key") == 3))
   }
 
   it should "allow to read rows as Tuple1" in {
@@ -222,7 +222,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple1(
       1: Integer
     )
@@ -237,7 +237,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple2(
       1: Integer,
       "2"
@@ -254,7 +254,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple3(
       1: Integer,
       "2",
@@ -273,7 +273,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple4(
       1: Integer,
       "2",
@@ -294,7 +294,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple5(
       1: Integer,
       "2",
@@ -317,7 +317,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple6(
       1: Integer,
       "2",
@@ -342,7 +342,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple7(
       1: Integer,
       "2",
@@ -369,7 +369,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple8(
       1: Integer,
       "2",
@@ -398,7 +398,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple9(
       1: Integer,
       "2",
@@ -429,7 +429,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple10(
       1: Integer,
       "2",
@@ -462,7 +462,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple11(
       1: Integer,
       "2",
@@ -497,7 +497,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11", "c12"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple12(
       1: Integer,
       "2",
@@ -534,7 +534,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11", "c12", "c13"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple13(
       1: Integer,
       "2",
@@ -573,7 +573,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11", "c12", "c13", "c14"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple14(
       1: Integer,
       "2",
@@ -614,7 +614,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11", "c12", "c13", "c14", "c15"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple15(
       1: Integer,
       "2",
@@ -657,7 +657,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11", "c12", "c13", "c14", "c15", "c16"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple16(
       1: Integer,
       "2",
@@ -702,7 +702,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11", "c12", "c13", "c14", "c15", "c16", "c17"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple17(
       1: Integer,
       "2",
@@ -749,7 +749,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11", "c12", "c13", "c14", "c15", "c16", "c17", "c18"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple18(
       1: Integer,
       "2",
@@ -798,7 +798,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11", "c12", "c13", "c14", "c15", "c16", "c17", "c18", "c19"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple19(
       1: Integer,
       "2",
@@ -849,7 +849,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11", "c12", "c13", "c14", "c15", "c16", "c17", "c18", "c19", "c20"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple20(
       1: Integer,
       "2",
@@ -902,7 +902,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11", "c12", "c13", "c14", "c15", "c16", "c17", "c18", "c19", "c20", "c21"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple21(
       1: Integer,
       "2",
@@ -957,7 +957,7 @@ class CassandraJavaUtilSpec extends SparkCassandraITFlatSpecBase with DefaultClu
     )).select(
         "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "c10", "c11", "c12", "c13", "c14", "c15", "c16", "c17", "c18", "c19", "c20", "c21", "c22"
       )
-      .collect().head
+      .collect().asScala.head
     tuple shouldBe Tuple22(
       1: Integer,
       "2",

connector/src/it/scala/com/datastax/spark/connector/SparkCassandraITFlatSpecBase.scala

@@ -200,8 +200,8 @@ trait SparkCassandraITSpecBase
     Await.result(Future.sequence(units), Duration.Inf)
   }
 
-  def awaitAll[T](units: TraversableOnce[Future[T]]): TraversableOnce[T] = {
-    Await.result(Future.sequence(units), Duration.Inf)
+  def awaitAll[T](units: IterableOnce[Future[T]]): IterableOnce[T] = {
+    Await.result(Future.sequence(units.iterator.toList), Duration.Inf)
   }
 
   def keyspaceCql(name: String = ks) =

connector/src/it/scala/com/datastax/spark/connector/cql/CassandraAuthenticatedConnectorSpec.scala

@@ -66,7 +66,7 @@ class CassandraAuthenticatedConnectorSpec extends SparkCassandraITFlatSpecBase w
       "spark.cassandra.auth.password" -> "cassandra",
       "keyspace" -> ks, "table" -> "authtest")
 
-    personDF1.write.format("org.apache.spark.sql.cassandra").options(options).mode("append")save()
+    personDF1.write.format("org.apache.spark.sql.cassandra").options(options).mode("append").save()
     val personDF2 = spark.read.format("org.apache.spark.sql.cassandra").options(options).load()
 
     personDF2.count should be(4)

connector/src/it/scala/com/datastax/spark/connector/rdd/CassandraJavaPairRDDSpec.scala

@@ -8,8 +8,8 @@ import com.datastax.spark.connector.cql.CassandraConnector
 import com.datastax.spark.connector.japi.CassandraJavaUtil._
 import org.apache.spark.api.java.function.{Function2, Function => JFunction}
 
-import scala.collection.JavaConversions._
 import scala.concurrent.Future
+import scala.jdk.CollectionConverters._
 
 case class SimpleClass(value: Integer)
 
@@ -103,15 +103,16 @@ class CassandraJavaPairRDDSpec extends SparkCassandraITFlatSpecBase with Default
         "key")
       .spanBy(f, classOf[Integer])
       .collect()
+      .asScala
       .toMap
 
     results should have size 2
     results should contain key 10
     results should contain key 20
-    results(10).size should be(3)
-    results(10).map(_._2).toSeq should be(Seq(10, 11, 12))
-    results(20).size should be(3)
-    results(20).map(_._2).toSeq should be(Seq(20, 21, 22))
+    results(10).asScala.size should be(3)
+    results(10).asScala.map(_._2).toSeq should be(Seq(10, 11, 12))
+    results(20).asScala.size should be(3)
+    results(20).asScala.map(_._2).toSeq should be(Seq(20, 21, 22))
   }
 
   it should "allow to use spanByKey method" in {
@@ -129,15 +130,16 @@ class CassandraJavaPairRDDSpec extends SparkCassandraITFlatSpecBase with Default
         "key")
       .spanByKey()
       .collect()
+      .asScala
       .toMap
 
     results should have size 2
     results should contain key 10
     results should contain key 20
     results(10).size should be(3)
-    results(10).toSeq should be(Seq(10, 11, 12))
+    results(10).asScala.toSeq should be(Seq(10, 11, 12))
     results(20).size should be(3)
-    results(20).toSeq should be(Seq(20, 21, 22))
+    results(20).asScala.toSeq should be(Seq(20, 21, 22))
   }
 
   it should "allow to use of keyByAndApplyPartitioner" in {